1. Field of the Invention
The present invention relates to an electronic appliance having a secondary storage device and particularly to an electronic appliance, for example, such as an electronic musical instrument, having a secondary storage device for storing data which can be easily divided into pieces under a plurality of predetermined items.
2. Description of the Related Art
Secondary storage devices such as magnetic tapes, floppy disks, hard disks, optical disks, and the like are widely used in electronic appliances such as computers, electronic musical instruments, and the like. Such a secondary storage device has a predetermined storage capacity. When the quantity of data storage has reached this storage capacity, the storage device becomes impossible to store data any more.
When generated or edited data are to be stored into such a secondary storage device through an input-output device of an electronic appliance or the like, all generated data are stored together with affix data such as file names for identifying the data.
In most cases, the portion to be subjected to alteration is partial in the same group of data, such as a program for controlling a certain electronic appliance, so that portions of the same data overlap each other in a plurality of data. In such cases, the constituent portions of the same data have had to be stored wastefully when different file names are affixed to the data are used.
As described above, a document or a file which is an unit of information treated in such a secondary storage device has been heretofore handled as one unit as a whole, so that portions of the document or file have been not noticed when the portions are written in or read out. Accordingly, information which is different only a portion thereof From other information has been stored as a file which is different from another file of the other information, so that the storage capacity of the secondary storage device has been consumed wastefully.